The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
This invention relates to underwater communications devices transmitting high levels of energy. More particularly, the underwater communications devices of this invention uses explosives to transmit coded high energy, broadband acoustic signals from remote unattended locations in response to interrogation signals.
Current methods of communicating signals underwater make use of piezoelectric and other electromechanical transducers to transmit acoustic energy into the water and have it propagate some distance to an in-water receiving transducer. The receiving transducer converts the received acoustic energy into electrical signals that are deciphered and translated into readable messages. Drawbacks inherent to the use of acoustic energy transmitted through the sea are many. Environmental factors all contribute to distort, degrade, mask, or inhibit the acoustic transmission of acoustic energy from the source to the receiver. Often traditional transducers emit acoustic energy in only a narrow band of wavelengths and, as such, are prone to signal deterioration due to biota absorbing these frequencies, thermoclines distorting their translation, etc. To overcome these environmental factors acoustic-transmitting arrays of great size requiring massive amounts of power and large electrical plants have been introduced. Typical of such systems are those found integrated aboard modern navy vessels. Unfortunately, these systems are very large and expensive and are not readily adaptable to being made constituents of deployable ordnance. Miniaturization of traditional transducer systems for incorporation into deployable ordnance always comes at a requisite reduction in useable available electrical power and, consequently, in the ability to communicate effectively over long ranges.
Thus, in accordance with this inventive concept, a need has been recognized in the state of the art for an in-water device used to report information to command platforms with high reliability of hearing the signal emitted from the device to allow responsive decisions to be made regarding movement and transit of maritime vessels.
The present invention provides an underwater high energy acoustic communications device. An inner shell-like structure has an outer surface connected to first ends of a plurality of tuning springs. An outer shell-like structure has an inner surface connected to second ends of the tuning springs to concentrically locate and space the inner and outer structures in a spaced-apart state of equilibrium. A plurality of explosive units are mounted on the inner surface of the outer structure. Each of the explosive units includes an explosive squib, a rigid tube, and a projectile. Firing signals from a micro-controller are fed over electrical leads to designated ones of the squibs of the explosive units to detonate them and fire their interconnected projectiles to strike the inner structure that emits ringing high-energy broadband acoustic signals that are propagated into surrounding seawater. A transducer connected to the micro controller receives specific acoustic signals from a remote source to produce representative signals that are connected to the micro-controller which in turn generates preprogrammed sequences of firing signals so that the explosive squibs are fired in varying rates to propagate various coded messages by the high-energy, broadband, acoustic signals.
An object of the invention is to provide a method of and device for producing high power communication signals from an in-water device using highly energetic explosive compounds.
Another object is to provide a method of and device for sending high power communication signals via highly energetic explosives to allow long range one-way omni-directional communications from ordnance, where size and electrical energy are limited, to a remote host platform. Another object is to provide a method of and device for using chemical energy in explosives to eliminate drawbacks associated with communication systems relying on traditional transducers.
Another object is to provide a method of and device for using explosives to provide more energy on a per unit volume and weight basis than electrical or mechanical transducer systems.
Another object is to provide a method of and device for unattended in-water high energy transmission using high energetic explosives at a remote location to accurately and acoustically report monitored information to distant command platforms to enable responsive decisions. Another object is to provide a method of and device for communicating using broadband acoustic signals significantly less affected by environmental factors influencing signal propagation than traditional electrically or mechanically driven transducer elements. These and other objects of the invention will become more readily apparent from the ensuing specification when taken in conjunction with the appended claims.